BIOL 251: Exam 3 (Latest
Update) Human Anatomy & Physiology I
with Lab | Questions & Certified Answers
| 100% Correct - Portage Learning
Quiz_________________?
What are the roles of calmodulin and myosin-light chain kinase
in smooth muscle cell contraction? -
Answer
Calmodulin binds Ca2+ and activates myosin-light chain
kinase, which phosphorylates myosin and initiates contraction.
Quiz_________________?
What is the function of phosphatase in smooth muscle cells? -
Answer
Phosphatase dephosphorylates myosin, leading to muscle
relaxation.
Quiz_________________?
List the mechanisms to remove calcium from the cytoplasm of
smooth muscle cells during relaxation. -
1
, Answer
Calcium is removed via the sarcoplasmic reticulum, calcium
pumps, and sodium-calcium exchangers.
Quiz_________________?
Where does the calcium needed for cardiac muscle cell
contraction come from? -
Answer
Calcium comes from both the extracellular fluid and the
sarcoplasmic reticulum.
Quiz_________________?
Describe the events that occur in excitation-contraction
coupling in cardiac muscle cells. -
Answer
Action potentials trigger calcium influx, leading to calcium-
induced calcium release from the sarcoplasmic reticulum,
resulting in muscle contraction.
Quiz_________________?
2
Update) Human Anatomy & Physiology I
with Lab | Questions & Certified Answers
| 100% Correct - Portage Learning
Quiz_________________?
What are the roles of calmodulin and myosin-light chain kinase
in smooth muscle cell contraction? -
Answer
Calmodulin binds Ca2+ and activates myosin-light chain
kinase, which phosphorylates myosin and initiates contraction.
Quiz_________________?
What is the function of phosphatase in smooth muscle cells? -
Answer
Phosphatase dephosphorylates myosin, leading to muscle
relaxation.
Quiz_________________?
List the mechanisms to remove calcium from the cytoplasm of
smooth muscle cells during relaxation. -
1
, Answer
Calcium is removed via the sarcoplasmic reticulum, calcium
pumps, and sodium-calcium exchangers.
Quiz_________________?
Where does the calcium needed for cardiac muscle cell
contraction come from? -
Answer
Calcium comes from both the extracellular fluid and the
sarcoplasmic reticulum.
Quiz_________________?
Describe the events that occur in excitation-contraction
coupling in cardiac muscle cells. -
Answer
Action potentials trigger calcium influx, leading to calcium-
induced calcium release from the sarcoplasmic reticulum,
resulting in muscle contraction.
Quiz_________________?
2
